Sanitation

care of water, all personally supervised by the officers. During the war also sanitary sections and sanitary squads, which are field units, have materialised and progressively improved. Sanitation is mainly concerned in the proper disposal of dirt in its widest sense, the dirt of the dictionary, or " matter misplaced." In a large army in the field there is a wonderful scope for the practice of cleanliness, affecting S?^' .^le water supply, the food, the person, if ^ing, and the quarters in which it lives, whether it be castle, " dug-out," or " bivouac."


Literature review
Most of the potato-growing states have information available on the general subject of potato production and particularly on disease control and sanitation practices. Few states, however, have this information listed under "sanitation." A number of state workers sent copies of their recommendations which had been prepared by potato specialists in the respective states. These pmnphlets are included in the bibliography listed at the end. Most of them are brief and prepared as circulars by the many states (1,2,3,12,15,17,20,21,22,23,26,28).
Undoubtedly other states have similar publications prepared primarily for use by their own potato growers. Idaho (6) has a very useful publication primarily on storage recommendations. Dykstra (9) in 1961 published an article on how to keep potatoes disease-free. The control of Rhizoctonia solani is reported by Graham (16) on the treatment of tubers with organic mercury compounds. Palm and Young (24) of Oregon studied the fungicidal activity of dichlone and captan and the bactericidal activity of Streptomycin sulfate, Streptomycin nitrate, maneb and terramycin, and noted that none of these were significantly reduced after aqueous mixtures of the fungicides and antibiotics had aged for one week. Maneb showed more bacteriocidal activity than Streptomycin but less than Terramycin. The general properties of Torsite detergent as a disinfectant were presented by Lorah (19). Bonde and Johnson (5) found that mercuric chloride, acidified mercuric chloride and copper sulfate were most effective for ring-rot control. Streptomycin sulphate was best of the antibiotics used. Most disinfectants gave better disease control when used in combination with Streptomycin sulfate than when used alone.
The general aspects of ring-rot control are summarized briefly by Dickens and Felton (7) in Colorado, by Fenwick and Ohms (13) in Idaho, and by Bissonnette and Benson (4) in North Dakota. Jute-log fumigation to eradicate ring-rot bacteria was demonstrated by Richardson and Monro (27). Paquin (25) in Canada found that among several chemicals, the antibiotic Albamycin was the sole compound to show a slightly greater disinfecting capacity than mercuric chloride, although the dipping time required was longer. Acidulated mercuric chloride retained its disinfecting capacity well in dipping successive lots of potato seed pieces.
Treatment for the prevention of seed-piece decay has been investigated by a number of workers. Duncan and Gallegly (8) of West Virginia found little or no benefit from seed-piece treatment when cutting, treating and planting operations were done on the same day. However, when seed was cut and treated one month before planting, some benefits were seen. Streptomycin, as used, caused a reduction in stand and yield while captan did not. Epps (11) working in South Carolina found that Streptomycin treatment (liquid or dust) of freshly-cut seed pieces resulted in good control of decay as measured by stand and yield. In tests Where seed-piece decay was not prevalent, the Streptomycin treatment still gave slight yield increases. Captan was inferior in these tests. Fink (14) in Pennsylvania reported increased stands and yields with seed treatment by Streptomycin, Spergon, Phygon, captan, nabam and ferham. Eide (10) found the decay of seed pieces was less when tubers had been stored at 49 F than when stored at 35 F. Decay was great in cut seed held nine days before planting. Captan reduced tuber breakdown. The variety Dazoc had most decay; Pontiac, intermediate; and Cobbler, least. Line and Eide (18) of Minnesota found that cut potato seed-pieces produced lower yields if stored several days after they were inoculated with soft rot and fusaria species and dipped in a chemical seed protectant. Even when seed was stored and inoculated with these organisms, decay did not ahvays increase over non-inoculated lots (for decay may occur without such inoculation). Maneb was generally superior against seedpiece breakdown.

1968]
STARR : SAI~ITATION 429 The effect of early planting on sanitation was reported by Ivanchenko (29) in Russia.

B. Seed treatments
Although seed treatments are not recommended for the control of bacterial ring-rot because of internal infection, there are cases where tuber surfaces may be exposed to ring-rot contamination and may warrant treatment. This is the reason for its inclusion in the questionnaire.
The subject of seed treatments is a broad one since many specific treatments are in use for the various diseases. It was planned to present the treatment results by different sections of the country, but since a large number of chemicals was reported by many states, a sectional division seemed unwarranted; thus, the results are presented generally from the certified seed-producing states in the North, and from the seedconsuming states in the South.
Now what are the prerequisites for a successful seed-treating material ? Certainly, first of all is the use of an effective disinfectant, --one that is safe to personnel, non-corrosive to metals, harmless to various materials used, and, if possible, pleasant to use. It also should be effective for more than one disease. Many chemicals meet most of these requirements, but few, if any, meet all of them with complete satisfaction.
In the present study it was thought advisable to tabulate the various seed-treating materials as reported in questionnaires from the various states in order to determine which materials are now in general use. Chemicals used as dips or liquid treatments are as follows: In the seed-consuming states of the South, seed treatments are of very little concern, since a preponderance of growers use certified seed from the northern states and depend upon that seed to be healthy and highly productive. Because there is little research done in these states on potato seed treatments, southern growers rely heavily upon other states to the north to provide the information needed.
Workers in many of the southern states reported that they have had no serious problems with bacterial ring-rot --one of the most troublesome of all diseases from the standpoint of sanitation.
3. Individual comments L. W. Nielsen of North Carolina reported that it has been about 15 years since ring-rot was observed in the table-stock acreage.
W. M. Epps of South Carolina stated, "Since we have so little ringrot, we are not concerned with this disease except to see that our growers use certified seed. In the 11 years I have been in the area, I saw ring-rot only once." T. J. Nugent of Virginia commented, "Apparently the personnel in the various states from which we get our seed have and are doing a good job in keeping seed-borne troubles to a mininmm. When ring-rot first became a problem, we had a few outbreaks of this disease in our area. Since that time the trouble has either not been here, or has been of such small consequence that we are not aware of its presence." C. E. Logsdon of Alaska reported, "Our data show that in cool climates such as ours, tile ring-rot bacterium can live nmch more comfortably with the potato than elsewhere and that we must make a constant effort to eliminate infected lots. This is almost a social disease: those who are afraid of it seldom if ever have the disease in the spuds, while those who do not believe it is a problem, almost invariably get it. Alaska has taken a very interesting step to control this disease through a new state regulation wbich the potato growers themselves asked for. This regulation reads as follows: all potatoes hereafter planted in the state shall be certified seed or seed that meets the disease tolerance of the Alaska Certified Seed Program --effective July 1, 1967." Comments on seed treatments, in general, were as follows: C. V~ r. Horne of Texas reported that their growers are reluctant to use a seed treatment chemical because they have difficulty in hiring personnel to operate the planters when these materials are used. However, some growers are using captan. F. L. Howard of Rhode Island stated, "I don't believe a single grower in Rhode Island treats seed." R. E. Ohms of Idaho commented, "We recommend seed treatments to prevent infection through the cut surface by soil-borne Pythium and Phytophthora. By preventing fungus seed-piece decay the secondary bacterial soft rot is controlled and the subsequent blackleg disease." Ohms added, "There are a number of chemicals that will do a satisfactory job in preventing seed-piece decay. There is more variation in the method of application and decay control than there is between chemicals." \u M. Epps of South Carolina stated, "Few of our growers use any chemical treatment, since we have been unable to show that it pays." L. W. Nielsen of North Carolina commented, "Fusarium seed-piece decay followed by blackleg is the major problem in the table-stock area. Fungicide dusts are becoming more popular although more expensive."

C. Storage facilities
In the northern states where the bulk of certified seed is produced, the sanitation of storage facilities is very ilnportant, for if this job is not done thoroughly, the business of producing seed can be jeopardized.
First is the cleaning-up process where old potato and soil debris must be removed completely before chemicals can act effectively.
Then the chemical selected for this purpose must be applied to all surfaces for effective results. This process should be completed well in advance of storage so that the storage quarters can be aired thoroughly before storing potatoes, particularly if a chemical such as formaldehyde is used.
The process of disinfestation of storage houses is a problem only in the .seed-producing areas, as seed is seldom stored in the southern states, m which case specialized storage is provided.
The following chemicals were listed for storage facilities by the states indicated below : 1. Chlorine compounds (Chlorox, B. K., Purex, etc., 5% solution) --Alaska, Idaho, Michigan, Ohio and Rhode Island.  a. Individual comments R. E. Ohms of Idaho stated, "We stress the use of soap and water or steam prior to the use of a chemical. As in the use of seed-treatment chemicals, the removal of dirt and old potato residue is more important than the particular chemical used for equipment and cellar disinfectant." California workers, D. H. Hall and A. R. Weinhold, advised, "Wash all surfaces thoroughly with hot water and strong detergent to remove all soil and debris. If the storage house has a soil floor, remove surface soil. Spray with copper sulfate solution." H. S. Potter and W. J. Hooker of Michigan also emphasized the importance of removing all dirt and trash from surface to be treated. They further stated, "Since formaldehyde is highly volatile and has a fumigating action, heated storages should be closed or treated equipment covered for 24 hours, then aired until there is no longer an odor." Arthur Hawkins of Connecticut recommended coal tar stock dip as one of three disinfectants for storage houses, etc. He did qualify this recommendation by saying, "To avoid injury and off-flavoring to tubers, I would not use coal tar disinfectant for bins if potatoes are to be placed into them shortly after application." D. Equipn~ent-(Planters, Trucks, Cutting equipment, Sacks, Etc.) Since much of this equipment is complex in structure, it is often difficult to reach all parts with a disinfestant. Potato and soil debris accunmlate on certain parts of this equipment and make it necessary to first thoroughly clean them before applying the chemical.
The following chemicals were listed for the treatment of equipment by the states indicated below: 11. Sacks (used) to be burned --New York and Vermont. a, Individual comment-E. L. Shannon of New Mexico stated, "Planters require disinfection at least twice daily and between each different seed lot planted." E. Clothing-(Boots, gloves, etc.) Many of those answering the questionnaire were not concerned with this section as it applied primarily to seed-producing states.
Where bacterial ring-rot is a factor, it is important to treat articles of clothing, particularly boots and gloves.
The following chemicals were listed for the treatment of clotlling by the states indicated below: 1. Alcohol (isopropyl) --Colorado.

III. GENERAL SUMMARY AND CONCLUSIONS
Sanitation covers a wide range of activities, particularly with seed disinfection, cleanliness with storage facilities, with potato machinery, and with articles of clothing.
The treatment of seed is an important activity in which a number of the old standard chemicals, though somewhat modified, are still popular --for example, Semeson Bel and more recently, captan. From the comments made by potato workers, it appears that treatments to prevent seed-piece decay are of foremost importance. Especially is this true with the dust treatments, captan and Polyram, used widely in the potatoproducing states. In a more limited way, captan plus Streptomycin dust is used to give added protection in cold, wet soils.
In storage-house disinfestation, copper sulfate continues to be popular,. especially for the floors and bins. Quaternary ammonium compounds are conunon, as well as chlorine formulations. Lysol and formaldehyde also have continued as standards. In some northeastern states, coal-tar products are still popular, especially for ring-rot, as to date, researchers have found nothing more effective. As some potato specialists have ably stated, "There is more variation between methods of application than between the chemicals used for general effectiveness." This statement is true, indeed, in many of the activities dealing with sanitation.
In the disinfestation of planters, cutting equipment, etc. the most important matter is that of getting equipment cleansed of contaminated debris before any chemical can become effective. Some workers have recommended that equipment first be washed thoroughly with hot water and a strong detergent to remove dirt before chemicals can be applied effectively. Steam, where readily available, is one of the most desirable methods especially for treating machinery. Mercuric chloride appears to be one of the most common and effective chemicals used to disinfest [Vol. 45 cutting knives. Most states recommend the discarding of used bags rather than treating them with a chemical. Boots and gloves should be decontaminated, particularly where ring-rot is present. A number of chemicals are recommended for this purpose, although some workers prefer to discard certain articles such as gloves. Some specialists recommend that clothing be washed with hot water plus a detergent, then treated with a chemical.
It appears that effective chemicals are available for complete disinfestation of equipment used in the potato industry. The need seems to be in the proper application of known information and this truly is a continuing job for certification officials, for county and state extension specialists, and certainly for potato growers.
The seed-consuming states depend entirely upon the producing states for quality seed through the application of proper production methods, coupled with rigid inspections by certification officials.
It then behooves the seed-producing states to do everything possible to keep seed free of insiduous diseases such as ring-rot; for, although little trouble is apparent at present, outbreaks can occur quickly if potato producers and researchers, alike, tend to become complacent.